Colorectal Adenocarcinoma in East Africa: A Narrative Literature Review

This paper is a review of work done on colorectal adenocarcinoma in East Africa showing geographic spread, age and sex ratios, clinical presentation, management and predominant histopathology. A steady increased incidence of CRC in East African countries is currently being documented however this is associated with a higher CRC-associated morbidity and mortality. Whilst the male: Female ratio varies between 1.2:1 to 1.88:1, up to 38% of CRC diagnosis are in patients younger than 40 years, in contrast to only 1.9% of CRC patients in Western developed countries such as the USA. Generally rectal carcinoma is more common than colon carcinoma and abdomino-perineal resections are commonly performed in up to between 54% - 71% due to the advanced stage of presentation of rectal tumours in East Africa. The late stage presentation and delayed effective treatment in East Africa may result in a higher morbidity in CRC patients. Interestingly there is a significant incidence of mucinous adenocarcinoma sub-groups compared to Western developed countries which carry a poor prognosis. A significant proportion of CRC patients have been found to have histological and demographic features which suggest that MSI-tumours and these tumours are more common in younger patients. However only a few authors have looked at the possibility of mismatch repair mutations in the genetic aetiopathogenesis of colorectal adenocarcinoma in East Africa.